The word karma has entered popular culture — and in the process, lost most of its meaning.
In casual usage, karma has become a kind of cosmic vending machine: do good things, good things happen to you; do bad things, and retribution follows. This is a moralized, simplified version of a far more subtle teaching.
The Sanskrit word karma simply means action. But action, in the Vedic understanding, is never isolated. Every action arises from a mental-emotional state (the intention, or sankalpa), creates an impression in consciousness (a samskara), and ripples outward into the world.
You are not punished for your anger. You are punished by your anger.
The teaching is not that good deeds are rewarded and bad deeds punished by some external judge, but that actions and their consequences are woven into the fabric of being itself.